Keoshkerian et al., U.S. Pat. No. 6,469,094 describes a process for the preparation of polymeric particulate materials employing a free radical polymerizable monomer, a free radical initiator and a stable free radical compound wherein the process includes a first bulk polymerization where controlled initiation and limited or partial monomer polymerization is accomplished for the purpose of preparing a prepolymer mixture followed by a second stage miniemulsion polymerization where substantially complete monomer polymerization is accomplished. To lower the cost of production, there is a need, which the present invention addresses, for new free radical polymerization processes that produce polymeric particles in a continuous mode.
Exemplary polymerization processes are described in the following:
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